486 Scientific Intelligence. 



almost black. Hardness about 5. "We shall defer further 

 mention of this mineral until we have examined it more 

 thoroughly. 



Fluorite, occurs in some abundance. Masses of a pale 

 greenish kind were found weighing fifty pounds tightly em- 

 bedded in the pegmatite. Purple and white shades have also 

 been foimd. A very opaque dark-purple kind has been found 

 in small masses. Its property of phosphorescing (green) when 

 gently heated has given rise to a great local interest in this 

 particular mineral. 



Gtjmmite, occurs sparingly, but we have not as yet been able 

 to find it in a sufficiently pure condition for examination. 

 Several varieties have been seen, and " yttro-gummite" is very 

 probably one of them. 



Tengerite (?) — In the cracks and fissures of the gadolinite 

 and yttrialite a white mineral rich in C0 2 is often noticed. 

 We have seen it in globular-radiated incrustations and in one 

 instance in distinct transparent isolated crystals. Dr. Genth 

 has already noted its occurrence and, as he observes, there is not 

 enough now obtainable to show its composition except by 

 qualitative tests. 



Fetid Gas. — Upon breaking some of the cyrtolite, while at 

 the mine, a fetid odor, quite different from H 2 S, was noticed. 

 Simply rubbing two massive specimens together is sufficient to 

 develop this very disagreeable smell. 



In conclusion, we take this opportunity to thank Mr Bar- 

 ringer, for his kind attentions and generous services extended 

 to Mr. Niven and to one of us while visiting this very inter- 

 esting locality. 



SCIENTIFIC INTELLIGENCE. 



I. Chemistry and Physics. 



1. On the Spectroscopic discrimination of the Rarer Earths. 

 — In his annual address as President of the Chemical Society, 

 Crookes has given a history of the so-called rare earths as they 

 have been brought to light and discriminated by the aid of the 

 spectroscope. In an interesting table he gives a list of the so- 

 called "rare elements" with which he has been special^ occupied 

 for the last seven or eight years; arranging in parallel columns 

 the names by which they are generally known, their atomic 

 masses, the formulas of the oxides, the manner in which they 

 come under the domain of spectroscopy, and the components or 

 meta-elements into which some of them have been decomposed, 

 first in 1886 by himself and then in 1887 by Kriiss and Nilson. 

 At first spectroscopic examination was applied directly to sub- 



